Detachable coupling



June 6, 1950 c PEPPER 2,510,653

DETACHABLE COUPLING Filed June 7, 1946 Zfl/lI/I/l/Aill:

IIIIIA lllllll INVENTOR Patented June 6, 1950 2,510,653 DETACHABLE COUPLING.

Carl P. Pepper, Plainfield, Ind., assignor, by mesne assignments, to The Marquette Metal Products Company, Cleveland, Ohio,

Ohio

a corporation of Application June'i, 1946, Serial No. 675,143

This invention relates to couplings for rotating shafts, and particularly to a quick detachable coupling especially adalptedfor easy attachment to and detachment from a driving shaft for driving relatively light equipment such, for example,

as tachometers and other test apparatus.

In many instances it is desirable to momentarily couple such a device to a rotating shaft and then to detach it therefrom without materially lowering the R. P. M. or otherwise affecting the operation of the shaft. Connection of the device to the shaft must alsc'be done with minimum jaror strain in order to protect the parts involved against injury.

An object of this invention is to provide an improved coupling of this type constructed and arranged to permit equipment to be readily and easily connected to and disconnected from a driving shaft during rotation thereof. A further object is to provide a coupling for driving light test equipment or the like constructed and arranged to permit such equipment to be readily clutched to a rotating shaft and then as readily detached therefrom without having to stop rotation of the shaft.

These and other objects which will be apparent are accomplished by the invention hereinafter described and illustrated in the accompanying drawing, which shows, in section, a coupling constructed in accordance with one embodiment of this invention operatively connecting a driving and a driven shaft together.

The present invention comprises a resilient clutch member having a socket for receivin the projecting drum-forming end'of a drive shaft to which the coupling is adapted to-be connected. The clutch member is usually directly connected to and made to form a part of the shaft to be 'driven, such as the operating shaft of a tachometer. The arrangement is such that positioning the clutch socket over the end of the driving shaft automatically causes the shaft to be drivingly engaged by the clutch member. A friction braking mechanism is provided whereby the clutch member is automatically disengaged from the driving shaft upon axial movement of the device relatively to the driving shaft. As a result of this feature, test equipment can be coupled to any suitable driving shaft by moving it into position over the end of said shaft, the axial movement of a part of the equipment "causing the declutching mechanism to function to prevent clutching engagement with the driving shaft until the equipment is in operative position. Likewise, movement of the equipment axially of the Claims. (01. 192-47)- shaft to remove it therefrom automatically actuates' the declutching mechanism to permitready removal; g

The illustrated embodiment of the invention Y is shown'in connection with a driving shaft l I provided with a projecting end [2 extending through a supporting bearing I3 into a socketl4 formed in the housing 15 on the mechanism, not shown, of which the driving shaft 1 i forms a part. The shaft- I2 is suitably prevented from moving endwise;

As illustrated, a shaft 16 to be driven, which may, for example, be-the-operatingshaft of a tachometer, or other test equipment, not shown,- has a boss or collar'l'l secured to the end thereof and located in a pocket l8 formed in the bearing.

housing IS of the shaft. A helical clutch spring 2| having a diameter slightly less than the diameter of the boss I! has one end frictionally engaging a clutch drum surface formed by the outer periphery of the boss H. The end of the boss has a beveled edge 22 to assist in assembling the parts. A clutch controlling (i. e. spring deenergizing) member in the form of an annular friction disc 23 is connected to the outer free end 24 of the clutch spring 2| in any desired manner, such as that shown in which the end of the spring'ishooked through a perforation formed in the friction disc. The friction disc 23 projects radially beyond the circumference of the spring adjacenta friction disc 25 fixedly attached to the innerend of the housing l9 defining the open end -of the pocket I8. I A second. friction disc '26 is located on the opposite side of the friction disc 25', being fixedly mounted on an inwardly extending radial flange 21 on a tubular casing 23 secured to and surrounding the projecting end of the housing I9. As illustrated, the casing has an outwardly projecting radial flange 29 with perforations adapted toreceive one or. more pins 3| projecting from the fixed driving shaft housing l5 when the coupling-is moved into clutching 'relatio-n therewith. There is enough free playbetween the driven shaft collar l1 and the bottom of-the pocket l8 to enable movement of the housing 19 along the driven shaft a sufficient amount to bring the friction disc 25 into operative engagement with the disc 23 of the clutch spring;

The clutch spring 2| must be selected with regard to the diameterof the terminal drum surface portion of the driving shaft l I to which it is to be clutched;- so that it will frictionally engage. the drum surface when positioned thereon. In other words, the inner diameter of the clutch spring is normally slightly less than the outer diameter of the drum surface. The free end of the driving shaft is beveled or rounded to aid the application of the spring thereto. As the housing I 9 is being slid into place the friction disc 25 bears against the friction disc 23 of the spring 2! with sufficient force to prevent the coils :of the spring from being energized into gripping relation to the drum surface of the rotating driving shaft. That operation requires only a very small restraining force providing it is applied to -thesfree end of the spring as through the hook 24. As soon are as the restraining force is relaxed athe spring automatically grips the driveshaftwith increase ing force from coil to coil. As theclutch spring picks up its torque load the flexibility of the free coils of the clutch spring between resl fiqtive drum portions of the two shafts absorbs the jar of engagement with the rotating shaft 'andthus protects the driven shaft and the associated mechanism; The coupling can ibeiad-apted for use with the shafts of difiierent diameters byselecting a clutch spring of the required diameter for suitable clutching operation. In ichanging from-one size springito another, it maybe ;-neces-- sary to-change the sprii igrsupporting bosscto obtain one having the :pro-perrdiameterzto hold ".the spring selected, or ;a spring "having lends rof :difrecent-diametersmaybeiemployed. 'Qther'shapes of springs may also be used as therewill-usually be no tendency for the turns of thespringrtoslip off the bossbecause-of the Wrapping downaction of the spring turns 'under rthe progressive coiling or straining forces pf tclutch engagement once the springl'has been released for .snch action.

Declutching of the spring from :the driving shaft is accomplished hy' movement of the housing ll! and associated friction' -facemfi axiallvnf the driving shaft 'tothe tight so as r'tolbring "said face 26 into engagementiwith=theiclutoh controlling friction disc 23 which-rotates freely with the clutch spring 21 as long as the latter is clutched to the driving-shaft. The'fidctionaiitesistance to rotation of the disc .23 is "transmitted to the deenergizing end 24 M the clutchaspring causing the associated "clutching portions thereof to be instantly unwrepped suiiiciently $016- lease the drivings'haft, thus-permitting .the hon sing 19 of the associated apparatus tobe :moved freely 'en'clwiseclear of the driving shaft. Thus'a deenergizing operation 011 the clutch spring is effected on endwise movement -of:thehousing 1:9 in opposite directions. so that all :of the desired number "of coils of the clutch spring '.'(as illustrated) can be applied in to full clutching a r-elationsliipto the driving shaft-"and removed therefrom during continued rotation -o'f sa'idshaft.

As illustrated, the engagement of the pins 3! with the radial flange =29 of tubiflar casing 28 prevents any tendency of the housing its to rotate with the driving -=sha ft when :the mechanisms are clutched together, thus "simplifying handling of the'dev'ice the operaitor. When the device is for use in connection with projecting driving shaft having no surrounding pocket, then the housing l9 must havea different form of support such as an attaching clamp of suitable form for engagement with-the housing such as 15.

Although the present invention has been described in connection with a'speciflc embodiment thereof it will'b'e apparent tha t it can be variously modified and adapted within-the "scope-of the appended claims.

I claim:

1. A coupling for detachably connecting a driven shaft to a rotating driving shaft, comprising a helical clutch spring mounted on said driven shaft and extending outwardly therefrom to provide an expansible socket for receiving the end of said driving shaft, said spring socket having a diameter when'unstrained suchthat engagement thereof with the surface of said driv- "ing shaft causes said spring to wrap down and contract said socket into engagement therewith to clutch said shafts together, a spring controling mechanism including a member connected "to the'end of said spring, and means responsive to movement axially of said driving shaft for engaging said member to resist the rotative movement .ofsaid :member so as to maintain the spring free from clutching engagement with said driving shaft whereby said coupling can be attached to or detached from said driving shaft during rotation thereof.

2. A coupling for detachably connecting a driven shaft to a-driving sha'ft, comprising a hell-- cal-clutch spring having one end mounted on said driven shaft and the other end projecting outwardly to form a socket :adapted to receive the end of said driving .wshafts-and 'to :be positioned in clutching engagement therewith by rotation of said shaft withini-said socket, and means responsive --'to movement axially of said driving shaft for declutching said spring therefrom-during rotation thereof.

3. A coupling for \detachably .=co.nnecting a driven shaft to a driving shaft, comprisingazhelical clutch spring havingcone end-mountedpn. said driven shaft and the other end projecting =outwardly' to form .a socket adapted' to receive the end'of said drivingshaft and tube .wpositionedzin clutching engagementtherewith, andameans responsive to and dependent upon-movement axially of said driving shaft iforzdeclutching said spring there from during rotation thereof said means bein operative only during the period-of said axial movement.

4. A coupling for detachably connecting :a drivenshaft to a rotating driving shaft, :comprising an a open end. helical clutch: spring having one (and mounted on -said:driven.-shaft and the other end projecting outwardly fronrsaid shaft :to :form

a socket adapted to :be'positioned rin clutching engagement with the proj ectingaendpf 5.3.3 16. dri ing shaft, a surrounding .socketzshaped housing member having friction -=surfaces thereon, and spring actuating means connected to-the .open end of saidspring in iipositionrto .zengage saiddrictiQn faces upon :movementof said .ahousing :member axially of said driven shaft whereby *to 'resist rotative movement of asaid spring-end under pulse of said driving lshaftvso as :change the diameter o'f :said spring socket :decl-utch said spring mm drivingrshaft;

5. A coupling for detachably connecting a driven shaft .to amotating adrivingsshaft, comprising anopeniendirheli cal clutchspring having one end mounted on saidvdrivenzshaftrand'the'other end projecting-outwardly 25mm Said;shaft to form a sooketadapted torbezpositioneddn. clutching engagement with :the proiecting end of asaid'driving shaft, .a surrounding socket shaped housin member having friction'isurfaces thereon, spring actuating means connected "to the QD 6 2 said spr in zpositionizto engage said friction faces upon .movementipf :housing .:memberaxially l-of said -.;dr iven shaft ;-Wher,ehv to re istpulse of said driving shaft so as to change the diameter of said spring socket to declutch said spring from said driving shaft, and means holding said friction faces against rotation. I

6. A coupling for detachably connecting a driven shaft to a rotating driving shaft, comprising an open end helical clutch spring having one end mounted on said driven shaft and the other end projecting outwardly from said shaft to form a socket adapted to be positioned in clutching engagement with the projecting end of said driving shaft, a surrounding socket shaped housing member having friction surfaces thereon, a spring actuating disc, a relatively movable friction surface and means for causing said surface to engage said disc, whereby to resist rotative movement of said spring end under impulse of said driving shaft so as to change the diameter of said spring socket to declutch said spring from said driving shaft.

7. A spring clutch unit comprising,.a circular driving drum, a coaxial driven member, a clutch spring having one end secured to the driven memher and coils normally in gripping relation to the drum, a third member normally rotatable with the spring and having a deenergizing con- 7 nection with the spring, and a' friction brake mechanism arranged to stop rotation of the third member to cause the spring to release the drum so that the drum can overrun the driven member.

8. A clutch comprising, a pair of axially aligned rotary members having circular drum surfaces, a helical clutch spring normally in tight frictional engagement with said drum surfaces, a third member normally rotatable with said drum members and having a normally non-operating deenergizing connection with said spring, and friction braking mechanism operable to arrest rotation of said third member to deenergize the spring in any rotated position thereof.

9. A coupling for detachably connecting two approximately coaxial rotary members during continuous rotation of one of them, said coupling comprising a self-energizing coil spring clutch element drivingly secured to one of the members and having a free end coil portion adapted and arranged to telescope a complementary drum surf ace of the other and automatically grip the drum surface by progressive coiling action of said coil portion, a spring deenergizing brake element secured to the'free end of said coil portion in a manner to enable prevention of such coiling action through restraint of rotation of said brake element, and a cooperating non-rotary brake means movable into and out of frictional engage- 1 ment with said brake element.

10. The coupling according to claim 9 wherein said brake means comprises spaced friction faces mounted in a common axially shiftable nonrotating housing which, when shifted axially in either direction from a neutral position, moves the brake means into operating engagement with the brake element to maintain the spring ineffective to grip the drum.

CARL P. PEPPER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 677,872 Locke July 9, 1901 1,126,780 Jones Feb. 2, 1915 1,718,197 Starkey June 18, 1929 2,024,947 Racklyeft Dec. 17, 1935 2,073,408 Litchfield Mar. 9, 1937 2,130,757 McCabe Sept. 20, 1938 FOREIGN PATENTS Number Country Date 197,178 Great Britain May 10, 1923 

